[SCSI] mpt2sas: Before removing sas_device search device in list for _scsih_sas_device_remove

Fix a oops in _scsih_sas_device_remove.  The driver was attempting to
delete a object from the sas_device link list when the object was not
present.

Added sanity check for sas_device NULL dereference.
before deleting sas_device now driver will search device in list then
only it will follow device removal.

Signed-off-by: Kashyap Desai <kashyap.desai@lsi.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

1 files changed, 8 insertions, 3 deletions

diff --git a/drivers/scsi/mpt2sas/mpt2sas_scsih.c b/drivers/scsi/mpt2sas/mpt2sas_scsih.c
index 77163bad75f9..c5ff26a2a51d 100644
--- a/drivers/scsi/mpt2sas/mpt2sas_scsih.c
+++ b/drivers/scsi/mpt2sas/mpt2sas_scsih.c
@@ -537,10 +537,15 @@ _scsih_sas_device_remove(struct MPT2SAS_ADAPTER *ioc,
 {
         unsigned long flags;
 
+        if (!sas_device)
+                return;
+
         spin_lock_irqsave(&ioc->sas_device_lock, flags);
-        list_del(&sas_device->list);
-        memset(sas_device, 0, sizeof(struct _sas_device));
-        kfree(sas_device);
+        if (mpt2sas_scsih_sas_device_find_by_sas_address(ioc,
+            sas_device->sas_address)) {
+                list_del(&sas_device->list);
+                kfree(sas_device);
+        }
         spin_unlock_irqrestore(&ioc->sas_device_lock, flags);
 }